Materials and methods: High performance liquid chromatography and light scattering were used to determine encapsulation efficiency, particle size, drug release, permeability and stability. Results: A high encapsulation efficiency 96.05 +/-+/- 1.77%% and a particle size of 83.52 +/-+/- 21.38 nm were obtained. Nearly 40%% of AEA remained in the NP after a 99.9%% dilution and only 50%% was released after 24 h at 37 degrees A degrees C with a 99%% dilution. PCL NP prevented the adsorption of the drug to polypropylene or polystyrene, but not to acrylic multiwell plates. Drug permeability through artificial membranes was low (10